Artificial denture.



No. 764,528. PATENTED JULY 5, 1904.

0. C. & J. R. HALDEMAN.

ARTIFICIAL DENTURE.

' APPLIOATION FILED APR. 6, 1903.

N0 MODEL.

A 52 jam 65 W UNITED STATES Patented July 5, 1904:.

PATENT OEEICE.

OLIVER C. HALDEMAN AND JOHN R. HALDEIVIAN, OF KANSAS CITY, MISSOURI, ASSIGNORS TO THE I-IALDEMAN PORCELAIN CROWN COMPANY, OF KANSAS CITY, MISSOURI.

ARTIFICIAL DENTUFIE.

SPECIFICATION forming part of Letters Patent N0. 764,528, dated July 5, 1904.

Application filed April 6, 1903. Serial No. 151,272. (No model.)

natural roots.

One of the objects of the invention is to provide a post'which is separable from the crown, so the latter maybe ground and otherwise manipulated in fitting it to the exposed end of the root.

A further object is to construct the lower end of the post in such a way that while it may be reliably secured to the crown the cavity in the latter to receive it Will be comparatively small, and consequently will not materially affect the strength of the crown.

In the accompanying drawings, which illustrate the invention, Figure 1 shows an enlarged vertical section of a root and crown, which latter is secured to the former by our improved post. Fig. 2 is an enlarged vertical section of a crown, showing the peculiar shape of the cavity arranged therein to receive the, post. Fig. 3 is an enlarged detail perspective view of our improved post and key employed in securing the crown to the root. Fig.4 shows a modified form of the crown and post.

In carrying out our invention we employ a crown l, composed of porcelain or other suitable material and provided with a peculiarshaped cavity 2, which is enlarged at its open end 3, is reduced at its inner end 4, and has a communicating angular portion 5, which of course does not have to extend toward the front surface of the tooth, as shown, but may extend in any other direction.

After the upper surface 6 of the crown has been ground to accurately fit the exposed terminal of root 7 the crown is furnished with the improved anchor 8, which tapers toward its upper end 9, has a reduced lower terminal 10, adapted to snugly fit into the reduced end 4 of cavity 2, and is provided with a lug 11 for engaging the angular portion 5 of the cavity.

After the lower end of the post has been inserted in cavity 2 it is removably locked therein by a key 12, which is slipped down between the wall of the enlarged portion of the cavity and that side of the post opposite from the angular lug 11, as shown in Fig. 1. By withdrawing said key the post may be readily detached from the crown by disengaging the lugfrom theangular portion of the cavity.

In addition to locking the post in position in the crown the key also reinforces it at joint 13 between the root and crown, so that Inastication of food is not liable to bend said post and loosen the crown from the root.

There is an occasional demand onthe trade for a crown provided with a filling. We meet this demand by extending the reduced portion 4 of the opening through to a depression 4" in the wall of the crown, which is plugged with a filling 14, secured to the terminal of an elongated reduced portion 10 of the anchor, as shown in Fig. I.

From the above description it is apparent that we have produced an anchor which is simple in form, inexpensive to Immufacture, and thoroughly reliable for the purpose. intended.

Having thus described our invention, what we claim, and desire to secure by Letters Patent, is

1. A crown provided with a rectangularcavity having a reduced terminal and an undercut angular portion communicating with one side thereof, a rectangular post having a reduced end adapted to enter the reduced terminal of the cavity, and a lug formed on the post near its reduced end adapted to enter the undercut angular portion in the crown, and a key for detachably locking the post in the crown.

2. A crown provided with a cavity having an undercut portion communicating thcrewith, a post adapted to fit into the cavity, a lug on the post adapted to fit into the undercut duced portion adapted to fill the depression in the wall of the crown, and a key for removably locking the post in the crown.

In testimony whereof We aflix our signatures I 5 in the presence of two witnesses.

OLIVER C. HALDEMAN. JOHN R. HALDEMAN.

Witnesses:

S. A. HIGKEY, F. G. FISCHER. 

